The present invention is directed generally to hand support devices and more particularly to an ergonomic hand support for use during a work operation to prevent, or significantly reduce, the risk of adverse medical conditions, such as Carpal Tunnel Syndrome.
Cumulative Trauma Disorder (CTD) is a broad generic term that is used to describe injuries that occur to the body as a result of actions which are repetitive in nature. In addition to affecting the associated nerve, the injury may also be caused to the tissue associated with it. There are several types of injuries that are associated with the hand, one of the most widely known is the Carpal Tunnel Syndrome. While it is an advanced stage of injury, a more common element of this condition is repetitive motion injuries to the tendons and ligaments of the wrist and hand.
Carpal Tunnel Syndrome has become to be known as a common and troublesome condition that interferes with the use of the hand. Typically, it is caused by a narrowing effect of the carpal canal leading to compression injury of the median nerve in the wrist. The carpal tunnel is a canal in the wrist through which the median nerve and flexor tendons pass from the forearm of a person to the hand. Among many causes, it is believed that prolonged, repetitive motion, such as at a keyboard or in a manual cutting operation in a poultry or meat processing/packaging plant, is the main factor for causing Carpal Tunnel Syndrome. Specifically, it is caused when too much pressure is exerted on the median nerve that extends through the wrist region of a person. A variety of factors are responsible for creating this pressure causing considerable pain to the affected person with the condition frequently worsening and resulting in permanent nerve damage.
In particular, there are four main factors which individually or together contribute to or cause this adverse medical condition of the hand. First factor is the gripping of an object by the hand. During a gripping action, carpal tunnel is compressed as a result of the surrounding tissues squeezing the median nerve, tendons and vessels that pass through the tunnel. This squeezing action can be observed by looking at the palm side of the wrist and closing and squeezing the hand.
The second aspect of the Carpal Tunnel Syndrome is a repetitive action by the hand which alone can be the cause of this condition. However, this condition is compounded when the gripping action takes place concurrently with the repetitive motion. In addition, improper arching of the wrist during the repetitive motion further contributes to compression of the carpal tunnel.
The third factor which contributes to or causes the Carpal Tunnel Syndrome is insufficient relieving of the pressure on the tunnel in between the repetitive action. For instance, if an adequate resting cycle is followed, the tissues can recover upon relieving of the pressure. If the period between cycles of motion is not sufficiently long, however, the tissues develop permanent injury occurring from prolonged contraction as a result of the compression of the tunnel.
Fourth and finally, improper positioning of the hand during use could also contribute to the syndrome. It is important to educate people about the proper and correct ergonomic use of the hand during a repetitive motion. With proper education, least amount of stress would be exerted to the body when an action of this type which causes this injury is performed. For example, limited or controlled exposure to a given adverse condition can be obtained by job rotation, etc.
Many hand support devices have been proposed in the art. Various examples are illustrated in U.S. Pat. Nos. 703,211; 1,583,754; 3,074,399; 3,885,249; 4,447,912; 4,883,073; 4,899,763; 4,149,296; 5,256,136; 5,214,799; 4,619,250; 4,502,688; 4,522,197; 4,850,341; 5,031,640; 4,203,495; 4,273,339; 4,624,016; 4,984,828; and 5,003,637; and PCT Publication WO93/00,834.
There is, however, a need in the art for an ergonomic hand support device which prevents or significantly reduces the risk of adverse medical conditions, or prevents from being compounded an already existing condition, such as Carpal Tunnel Syndrome.